Pacerift
GPS route, speed, acceleration and braking analysis using the Android phone you already carry. Offline capable, free, and no extra logger required.
Explore the app ↗TOOLS FOR DIFFERENT RIDES
Pick your
setup.
Choose by the data you need and the gear you want to carry.
Motorsport logger
Purpose-built hardware can provide higher-rate positioning and direct mounting options. It adds equipment cost, installation and a separate data workflow.
Navigation unit
Built to keep a route and directions visible. Detailed post-ride acceleration, braking and motion analysis may require another tool.
Add chassis sensing when you need it.
The Pacerift Compact Pod is intended to add hard-mounted motion sensing and more analytics. The phone app remains useful on its own.
Learn about the Compact Pod ↗Capabilities vary by device and setup. Phone-based speed and motion analysis is not calibrated motorsport instrumentation.
04 / TELEMETRY LAB
Corner speed.
Made tangible.
See how speed and corner radius shape lateral acceleration and an idealized lean estimate. Adjust either control; the readout updates instantly.
Open the full Telemetry Lab ↗ TURN MODELEDUCATIONAL ESTIMATE
LATERAL ACCELERATION0.91 g
IDEALIZED LEAN42.3°
Ideal coordinated-turn model only. Not measured vehicle data or a riding recommendation.
[ 🛠️ Technical Telemetry & Signal Engineering Specs ]EXPAND SPECS ＋
Engineering notes for riders who want to understand how GPS and inertial signals become a readable ride profile. These are processing concepts, not a claim that a phone replaces calibrated chassis-mounted motorsport instrumentation.
Butterworth smoothing
A low-pass Butterworth response attenuates high-frequency noise while retaining the ride-scale motion that matters. For order n and cutoff fc, the squared magnitude response is:
|H(jω)|² = 1 / (1 + (ω / ωc)2n)Cutoff selection trades noise rejection against transient response. Filtering should preserve acceleration and braking events rather than over-smooth them.
Hampel rejection
For samples in a local window, compute the median m and median absolute deviation (MAD). Flag an outlier when:
|xᵢ − m| > k · 1.4826 · MADThe scale factor makes MAD comparable to standard deviation for normally distributed noise. A flagged sample can be replaced with the window median or marked for downstream handling.
Quaternion rotation
Orientation quaternions rotate measured acceleration from device coordinates into a chosen reference frame:
aworld = q ⊗ adevice ⊗ q⁻¹Gravity compensation and axis alignment help estimate linear acceleration. Orientation drift and phone placement remain sources of uncertainty.
Useful relationships
Longitudinal acceleration is estimated from velocity change over time. For a turn at speed v and radius r, lateral acceleration is:
alat = v² / r G = a / 9.80665 m·s⁻²An ideal coordinated-turn lean estimate follows tan(θ) = v²/(r·g). Phone-only estimates are affected by mounting, vibration, road camber, tire dynamics and sensor drift.
PHONE SENSORS SUPPORT RIDE ANALYSIS · THE OPTIONAL PACERIFT POD IS DESIGNED TO ADD DIRECT CHASSIS MEASUREMENT
READY WHEN YOU ARE
Make every ride
count.
FREE · OFFLINE READY · ANDROID